Nancy C. Reardon

B. Sc. Honours Thesis

The Chemical Composition of Granite-Related and Mineralization-Related Tourmaline in Nova Scotia

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Tourmaline is a common accessory mineral which occurs in a wide variety of mineralogical settings. This mineral is commonly found in sedimentary, metamorphic, and granitoid intrusive rocks and their associated aplites, pegmatites and hydrothermal aureoles (greisens). Tourmaline is also frequently found in association with many types of mineral deposits. These include massive sulfides, polymetallic sulfides, vein and breccia Sn, vein Au, Sn and Mo greisens and Be-Li pegmatites. The chemical composition of tourmalines from occurrences of these types in Nova Scotia has been determined by microprobe analysis for SiO₂, TiO₂, Al₂O₃, FeO, MnO, MgO, CaO, Na₂O, K₂O and F. Both cores and rims of all grains were analyzed to determine possible chemical zoning; many grains show colour zoning. These analyses have shown distinct relationships exist between tourmaline composition and geological setting, however, significant overlap occurs among many of the groups studied. Chemical compositions and trends seen on binary plots for the elements analyzed are similar to those observed for tourmaline occurrences elsewhere. Boron isotope analyses were also carried out, however, no relationship between tourmaline paragenesis and boron isotope composition is evident.

Keywords:
Pages: 144
Supervisor: D. Barrie Clarke

Updated March 2010

After graduating, I worked for the Geological Survey of Canada mapping in the western Northwest Territories, in the Great Bear Lake area - thus the name of my company - Great Bear Geological Services Inc. I completed an M.Sc. at U of Ottawa/GSC in 1992. I've been consulting in mineral exploration since 1993, and have gained experience with a variety of commodity and mineral deposit types, including gold, VMS and SEDEX systems, working all over the Americas. I'm now based in Perth, Western Australia and exploring for gold in New Zealand and Australia.